Approximately 80% of children with cancer endure treatment-related symptoms. These symptoms can profoundly impact the child's life and lead to delays or reductions of treatment affecting prognosis and declines in physical and mental functioning affecting quality of life. Early symptom management is imperative to minimize these negative effects; however, symptoms must first be recognized. Symptom assessment is a core clinical responsibility of pediatric oncology nurses but best practices to identify symptoms among children receiving cancer treatment have not been established. Recognizing this gap, the Children's Oncology Group (COG) Nursing Discipline is proposing a one-day conference, ?Symptom Assessment during Childhood Cancer Treatment: State of the Science Symposium? to develop recommendations for best practices in symptom assessment and prioritize symptom related research questions in children undergoing cancer treatment. The COG Nursing Discipline has a history of success in discovering best practices and is well poised to achieve the specific aims in this proposal. This proposal provides a unique opportunity for convening a scientific symposium that brings together clinical and research experts; we will leverage the ongoing programs of symptom research among nurse researchers and the experience among COG clinicians and patient advocates to stimulating dialogue, discussion, and expert consensus-building regarding symptom assessment and symptom research in pediatric oncology. The expert consensus developed during the symposium will result in dissemination of best practice recommendations that will lay the groundwork for practice change and prioritize future symptom research for children diagnosed with cancer. Early identification of symptoms and children at risk for worse symptoms will allow prompt implementation of interventions to mitigate symptoms. Identifying best practices for symptom assessment has the potential to significantly reduce symptom distress and improve prognosis and quality of life for children receiving cancer treatment.